In western democracies like the UK, the USA and Canada, the role of the supreme court can be revealing. Constitutionally, it is straightforward enough – the court lays down the law, and the other civil institutions listen carefully and respond.

But this can be stressful for the institutions and the politicians who inhabit them. A politician's ears must be exquisitely attuned to every subtle harmony in the symphony of power; a supreme court decision can burst through the music like a jack hammer starting up in the lobby. How institutions respond to that kind of stress can reveal the political and cultural peculiarities of the democracies involved. Three recent cases show just how peculiar a political culture can get.

Last week, barely 100 days into its existence, the supreme court of the UK (SCUK) demonstrated that it well knew its proper place in the political pecking order.

In one of its first judgments, on the Treasury's precipitate freeze of bank accounts belonging to several terrorism suspects, the court used words like "paralysing", "draconian" and "unrestrained encroachments on personal liberty" to describe the actions, when chancellor, of the man who is now the UK's supreme elected official, Gordon Brown.

The Treasury responded immediately, with the announcement that it would introduce "fast-track" legislation to remedy the situation – and allow it to keep doing legally what the court decreed it was doing illegally.

It goes to show who is in charge. When the supreme court says "Jump!", the government might not ask "How high?" – but they do run and get a ladder.

Similarly last month, the supreme court of the United States (Scotus) overturned not only a century of legislation designed to limit corporate money in federal elections, but several of its own precedents as well.

The decision was harshly criticised, even within Scotus itself. Justice John Paul Stevens, dissenting from the bare 5-4 majority, described his colleagues' arguments as "backwards", "incorrect" and "a rejection of common sense" – in legal circles, the sort of language that might have provoked gunplay in the Republic's more virile days.

Even Obama attacked the court smack in the middle of his state of the union address, an unusually combative move. And in Congress, Barney Frank, chairman of the house financial services committee, and Chris Dodd, chairman of the Senate banking committee, began talking of ways to counter the potentially disastrous effects of the decision on the American electoral process.

Here again, it's a supreme court. Congress may disagree with it. The president may complain about it. But nobody suggests that the government could just flat-out ignore it.

For that, we go to Canada. The supreme court of Canada (SCOC) last week announced its decision in the case of a young Canadian citizen, Omar Khadr, who has been a prisoner of the US military at Guantánamo Bay for the past eight years since he was 15 years old. The Canadian government had appealed the decision of a lower court, which had ordered the government to request Khadr's repatriation from the Americans – as the British and Australian governments did years ago. (The last British prisoner at Guantánamo was repatriated in 2005.) Khadr has never been convicted of any crime.

In a unanimous ruling, SCOC agreed with the lower court on every major point – that the government had denied Khadr's constitutional rights, shirked its own international obligations, and defied the principles of fundamental justice. The court insisted that the government is obligated to rectify this compounded perfidy, but stopped short of ordering it to request repatriation, or ordering any other specific policy step – in effect, demanding that the government come up with its own plan to fix the mess it's made.

Yet the Canadian government, bewilderingly, declared victory. The minister of justice released a statement of under 100 words, claiming the court had "ruled that the government is not required to ask for accused terrorist Omar Khadr's return to Canada". As for what the court did say the government is required to do, well, there wasn't space to go into that.

And since the Canadian government has already placed its parliament on temporary redundancy, there'll be no irksome questions in the House, either.

Three different supreme courts – three very different political and cultural responses. The British seek accommodation; the Americans slug it out. The Canadians simply pretend nothing happened.

In our shared form of democracy, the court may be the highest legal authority in the land. But in Canada, a bland indifference reigns supreme.